Conventionally, ozone has been used to perform sterilization and disinfection of treated water of water supply and sewerage (tap water, ground water, or the like), deodorization and decolorization of industrial water, bleaching of pulp, sterilization of medical equipment, or the like.
However, although even oxidization by ozone has been able to perform hydrophilization and degradation, it has not been able to perform mineralization. Hardly decomposable organic matter such as dioxin and 1,4-dioxane has not been able to be decomposed by oxidation by ozone.
Given these circumstances, in decomposing these substances, it is general to perform oxidative decomposition using the hydroxyl radical, which has stronger oxidizing power than ozone.
For the formation of hydroxyl radicals, generally used methods in water treatment include a method that irradiates ozone-containing water with ultraviolet rays, a method that adds ozone to hydrogen peroxide-containing water, a method that irradiates hydrogen peroxide-containing water with ultraviolet rays, and a method that uses all hydrogen peroxide, ozone, and ultraviolet rays in combination.
Two or more of hydrogen peroxide, ozone, and ultraviolet rays are thus used in combination, a water treatment apparatus using the strong oxidizing power of the hydroxyl radical has a problem in that an initial cost and an operating cost are high.
In view of the above circumstances, a design of an apparatus that efficiently produces hydroxyl radicals and that causes the produced hydroxyl radicals to efficiently contribute to reaction can reduce the initial cost. It is desired to provide operation control with which sufficient hydroxyl radicals are produced for treatment.
Given this situation, if the concentration of hydroxyl radicals is continuously measured, efficient operation control is achieved. However, although hydroxyl radicals have strong oxidizing power, they have short lifetime and are required to be measured on the spot after being produced; the measurement is thus difficult under the present circumstances.
A method that produces a spin adduct using a spin trapping agent such as DMPO for measuring hydroxyl radicals and performs measurement by ESR has been proposed as a technique for measuring hydroxyl radicals.
A method that, using a characteristic of indoxyl-β-D-glucuronide as a component present in urine or blood easily reacting with hydroxyl radicals, measures the concentration of indoxyl-β-D-glucuronide in terms of fluorescence intensity or absorbance has been proposed as a medical application; and both methods use reagents.
However, both of the above methods have difficulty in continuously measuring hydroxyl radicals produced in an apparatus.
The present invention has been made in view of the above circumstances, and an object of embodiments is to provide an apparatus for measuring hydroxyl radicals and a liquid treatment apparatus that can continuously measure hydroxyl radicals without influencing the water quality or the like of a treatment system in water treatment facilities or the like.
An apparatus for measuring hydroxyl radicals of an embodiment is an apparatus for measuring hydroxyl radicals that measures hydroxyl radicals produced by irradiating a liquid to be treated flowing through a channel in which an ultraviolet lamp is installed with ultraviolet rays.
A diverting unit has a diverting channel that diverts the liquid to be treated before being irradiated with ultraviolet rays from the channel and part of which is arranged at a position enabling the liquid to be treated within the channel to be irradiated with the ultraviolet rays.
A reagent adding unit adds a hydroxyl radical measuring reagent to the diverted liquid to be treated.
A measuring unit irradiates the diverted liquid to be treated with the ultraviolet rays and measures the amount of hydroxyl radicals produced based on a change in the hydroxyl radical measuring reagent between before and after the irradiation with the ultraviolet rays.